Punching bags for training in boxing, martial arts, or other physical fitness activities are subjected to a great variety and number of forces, generally of great magnitude, during the use of such bags. These forces include torsional forces caused by blows to the bag which would otherwise cause the bag to rotate. The bag also experiences vertical forces caused by either vibration of the bag itself, or by vertical components of the blows exerted on the bag.
The above-described forces tend to concentrate at locations from which the punching bag is suspended, such as the tabs or other attachment mechanisms on the upper end of a suspended punching bag. As such, the torsional and vertical forces applied to the bag during its use may cause the bag to fatigue or wear prematurely, especially at the attachment points where stresses are concentrated. The deleterious effect of these forces is all the more severe when the bag is being freely suspended, as is normally the case, and when the bag is one of the so-called "heavy" bags, generally filled with sand or water and weighing up to 150 lbs.
It is therefore desirable to reduce or eliminate unnecessary forces which would otherwise arise during use of the punching bag. One approach to relieving stresses caused by rotation of the bag is to mount the bag with a swivel or similar connection which pivots or rotates in a substantially horizontal plane. While this approach may assist in relieving torsional stresses, it does little or nothing to address the vertical forces, vibrations, and other non-rotational forces experienced by the bag during its use.
Another mounting technique, such as shown in U.S. Pat. No. 5,725,458 makes use of a helical spring connected in series between the I-bolt of the mount and the top of the punching bag to be suspended. While this attempted solution may reduce some of the vibrational forces experienced by the punching bag so suspended, it has various drawbacks and other disadvantages. For example, in order to maintain a robust mounting connection to the structure supporting the punching bag, the helical spring is simply connected in series to an I-bolt of the supporting structure.
As a result, the helical spring extends downwardly from the vertical location where the punching bag would otherwise be suspended. The weight of the punching bag also extends the length of the spring by a predetermined amount. The serial attachment of the spring, and the fact that the spring is in tension when the punching bag is suspended thereon, both lower the actual height at which the punching bag is suspended. By lowering the height of the mounting location of the punching bag, the height of the punching bag itself is lowered by an amount at least equal to the length of the helical spring and the amount of its extension under tension. The mounting location height is lowered still further if a swivel connection is added above or below the helical spring, as is sometimes done currently.
The lowering of the punching bag is particularly significant when a bag is suspended from an indoor mounting structure or from a standard ceiling with a height of only about 8 feet. In such situations, the bag may be undesirably low for users beyond a certain height. In addition, if the bag is used by such users, the forces normally exerted on the bag are exerted even closer to the top of the bag, compounding the already extreme stress concentrations occurring at the attachment points at the top of the bag.
The extended length of the helical spring configuration described in U.S. Pat. No. 5,725,458 also increases the likelihood that the heavy bag will swing undesirably during its use. More particularly, increasing the distance between the mounting location of the bag and the top of the bag increases the moment arm of the forces acting on the punching bag as a result of blows received thereon. As a result, forces on the bag can more readily displace it, thus starting it to swing. Such swinging often interferes with the "rhythm" or effectiveness of the workout for which the bag is being used. Furthermore, the increased moment arm further concentrates stress on the aforesaid mounting locations, leading again to premature wear or fatigue.
The costs and inconvenience of replacing or repairing exercise equipment make it all the more imperative to avoid premature fatigue or degradation of such exercise equipment.
There is thus a need for a mount for exercise equipment which relieves not only torsional stresses, but also absorbs and thereby reduces longitudinal forces and vibrations, all without unnecessarily lowering the height at which the bag is suspended.
There is a further need for a mount to be versatile and useful in connection with a variety of support structures for exercise equipment.
There is yet a further need for such a mounting structure to be robust enough to operate as intended in the sometimes harsh conditions of supporting a heavy punching bag subjected to repeated blows or pummelings, often of great magnitude.